The environmental pollutant cyclopental(cd)pyrene or cyclopenteno(cd) pyrene (CPEP) is a carcinogenic compound, whereas cyclopentano(cd)yrene (CPAP), the 3,4-dihydro derivative of CPEP, is inactive, CPEP, CPAP, CPAP-cis-3,4-diol and CPAP-4-OH are mutagenic in diploid human lymphoblasts when activated by rat liver postmitochondrial supernatant (PMS), while other derivatives such as CPAP-trans-3,4-diol and CPAP-3-OH are nonmutagenic. The results from studies of this series of compounds indicate our proposed work can be useful in disclosing similarities and differences between mutagenesis and carcinogenesis at the molecular level. Diploid human lumphoblasts (cell line TK-6) with rat liver PMS and a new cell line AHH-1, which contains monooxygenase enzymes, will be used for mutagenicity studies, while mouse skin will be used for carcinogenicity studies. To achieve these aims we plan to compare: (1) The tumorigenicity of the mutagenic CPAP-cis-3,4-diol vs. the nonmutagenic CPAP-trans-3,4-diol and the weakly mutagenic CPAP-4-OH vs. the nonmutagenic CPAP-3-OH by repeated application and initiation-promotion on mouse skin. (2) The relative mutagenicity of CPEP, CPAP, CPAP-cis-3,4-diol, CPAP-trans-3,4-diol, CPAP-3-OH and CPAP-4-OH in the AHH-1 cell line. (3) The extent of binding the CPEP, CPAP and BP to mouse skin DNA and RNA after varying lengths of treatment and the corresponding level of aryl hydrocarbon hydroxylase and cytochrome P-450. (4) The extent of binding of CPAP-cis-3,4-diol and CPAP-trans-3,4-diol to mouse skin DNA and RNA at the optimum time determined above for CPEP. (5) The extent of binding of BP, CPEP, CPAP, CPAP-cis-3,4-diol, CPAP-trans-3,4-diol, CPAP-4-OH and CPAP-3-OH to DNA in diploid human lymphoblasts and in AHH-1 cells. We will analyze and compare by HPLC both: (6) The deoxyribonucleoside adducts of CPEP, (b) diploid human lymphoblasts treated with CPEP by PMS, (c) AHH-1 cells treated with CPEP, (d) calf thymus DNA incubated with CPAP-3,4-epoxide, and (7) The deoxyribonucleoside adducts of CPAP-cis-3,4-diol from hydrolyzed DNA obtained from (a) mouse skin treated with CPAP-cis-3,4-diol, (b) human lympoblasts treated with cis-diol in the presence of PMS, (c) AHH-1 cell line treated with the cis-diol, (d) calf thymus DNA incubated with CPAP-cis-3,4-diol-9,10-epoxide.